'use client';

import { createContext, useContext, useEffect, useState } from 'react';

type Theme = 'dark' | 'light' | 'system';

type ThemeProviderProps = {
  children: React.ReactNode;
  defaultTheme?: Theme;
  attribute?: string;
};

const ThemeProviderContext = createContext<{
  theme: Theme;
  setTheme: (theme: Theme) => void;
}>({
  theme: 'system',
  setTheme: () => null,
});

export function ThemeProvider({ children, defaultTheme = 'system' }: ThemeProviderProps) {
  const [theme, setTheme] = useState<Theme>(defaultTheme);

  useEffect(() => {
    const root = window.document.documentElement;
    root.classList.remove('light', 'dark');

    if (theme === 'system') {
      const systemTheme = window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
      root.classList.add(systemTheme);
      return;
    }

    root.classList.add(theme);
  }, [theme]);

  return <ThemeProviderContext.Provider value={{ theme, setTheme }}>{children}</ThemeProviderContext.Provider>;
}

export const useTheme = () => {
  const context = useContext(ThemeProviderContext);
  if (context === undefined) throw new Error('useTheme must be used within a ThemeProvider');
  return context;
};
